The goal of the proposed research is the elucidation of the mechanisms of protoplasmic streaming in Nitella and Physarum. We have performed an extensive characterization of the flow in both organisms using laser Doppler spectroscopy. This research has led us to a better understanding of the possible mechanisms which may provide the motive force for streaming. The work of many investigators has led to the clear implication of contractile proteins in this process. Such a contractile apparatus would require ion transport. We propose a series of experiments on these two organisms which will apply fluctuation spectroscopy to the analysis of their dynamic electrical behavior. Autocorrelation, cross-correlation, and spectrum analysis equipment already in our possession will be used to analyze fluctuations in electrical potential on the surfaces and across the surfaces of these organisms. Results will be interpreted in terms of correlation of flowing particles in the protoplasm, transport of ions across membranes and walls, and characteristic fluctuation frequencies and frequencies of propagation of the contractile apparatus itself.